Obesity is a significant public health problem and is associated with increased postmenopausal breast cancer incidence and mortality. Among cancer patients, being overweight or obese has been associated with an increased risk for cancer recurrence and several comorbid conditions that may contribute to shorter survival and decreased health-related quality of life (HRQOL). Compared to White breast cancer survivors, Black breast cancer survivors are more likely to be obese and gain weight during treatment. Little is known about which strategies can help these women achieve or maintain a healthy weight after breast cancer treatment. Factors that may influence higher obesity in this group include, attitudes (e.g., preferences for certain foods), culture (e.g., beliefs about food), subjective norms (e.g., perceived support to make changes), and perceived control (e.g., self-efficacy in adhering to lifestyle guidelines), all of which may be amenable to change through appropriately targeted interventions. Additionally, factors associated with cancer survivorship such as fear of recurrence may also be important in the adoption of healthy lifestyle behaviors but have not been addressed in physical activity or dietary interventions with Black survivors. Given that Black survivors experience worse breast cancer outcomes than their White counterparts, interventions that facilitate weight loss in this group are needed. Guided by tenets from the Theory of Planned Behavior (TPB), we propose to intervene with sedentary overweight and obese Black survivors (6 months to 5 years post treatment) to address these gaps. We will conduct a 12-week two-arm pilot RCT to teach behavioral skills, provide social support and increase women's self-efficacy in performing recommended physical activity and dietary behaviors. In the RCT, 120 women will be randomly assigned to either a usual care control (C;n = 60) or intervention (I;n=60) arm. The intervention arm will receive pedometers, attend 6 group sessions and receive 6 individual phone motivational interviewing sessions delivered by a trained peer (survivor coach). At the groups, women will receive individual physical activity and dietary "prescriptions" (e.g., 10,000 steps per day) and participate in group activities (e.g., group walks, nutrition demonstrations). Coaches will tailor phone sessions according to survivors'baseline TPB tenets (e.g., attitudes, social/cultural norms) and serve as a source of support. Follow-up assessments will occur at six weeks and one month after the intervention. Study aims are to: 1) examine the feasibility and acceptability of a survivor-focused behavioral weight control intervention;2) explore intervention main effects on body mass index (BMI, kg/m2), physical activity, and dietary behaviors;and 3) explore the intervention's effect on ratings of HRQOL. This proposal meets national goals of reducing disparities and focuses on an underserved population. If promising, findings will be used to inform a larger intervention and a longitudinal RCT aimed at improving breast cancer outcomes. PUBLIC HEALTH RELEVANCE: Obesity is a significant public health problem and is associated with increased postmenopausal breast cancer incidence and mortality. Compared to White breast cancer survivors, Black breast cancer survivors are more likely to be obese and gain weight during treatment. Few studies have documented successful strategies in this underserved group. This study will assess the feasibility and acceptability of an intervention to improve physical activity, dietary behaviors, body mass index, and health-related quality of life in overweight and obese Black breast cancer survivors. If successful, a larger longitudinal study will be conducted to assess the effectiveness of the intervention on reducing obesity and breast cancer outcomes.